We take current - controlled dc / dc boost converter with feedback as a computer simulation example and explain the mechanism ; the simulation results demonstrate that by making use of chaos inherent in dc / dc boost converter and controlling parameters we can reduce emi level of the switched - mode power supply without any additional circuits being involved 以具有反馈环路的dc dcboost型变换器为对象,进行了机理阐述和计算机模拟。所得结果表明,利用开关模式电源中固有的混沌现象,通过简单的组合参数控制就可以在不附加任何外围电路的情况下降低开关模式电源的电磁干扰水平。